The myth of the Design & Build Bargain

“Design & Build sounds like a dream, doesn’t it? One team, one contract, one price — simple, right?”

But here’s the truth:

When you sign up for a Design & Build contract thinking you’re getting a bargain, you’re probably giving away more control, quality, and value than you realise.

In this blog, I’m going to show you why the Design & Build model often ends up costing more — in missed opportunities, poor outcomes, and short-term thinking.

What is Design & Build?

Let’s define it properly:

In a Design & Build contract, the contractor is responsible for both:

• Finalising the design

• Building the project

  
  

The client typically appoints a team for early-stage design and planning — and once approved, they hand it off to the contractor who takes over the rest, including technical design.

Sounds simple. Less risk. Fixed price. Right?

But here’s the problem:

The person now managing your design… is the same person managing your cost and programme.

And their incentive? To deliver it cheaper and faster — not necessarily better.

Where it Falls Apart

Let me walk you through what often happens:

🎯 1. Quality Drops Quietly

• Contractor value-engineers materials without fully understanding the design intent.

• Subtle changes accumulate: thinner insulation, downgraded finishes, different window systems.

• By the time you notice, it's too late — or too expensive to undo.

  
  

🧩 2. Design Becomes Fragmented

• Specialist subcontractors fill in gaps without anyone owning the whole picture.

• Nobody’s coordinating the full user experience — just ticking off pieces.

  
  

📉 3. You Lose the Architect

• Once the contractor takes over, the architect is no longer contractually working for you.

• They become novated — which means their loyalty, their scope, and even their influence is drastically reduced.

  
  

At that point, the person who was originally protecting your vision? They’re now working for your builder.

The "Savings" you never see

Clients love Design & Build because of the fixed price.

But let’s talk about what doesn’t show up in the tender price:

• 🧯 Fire strategy errors not caught until site

• 📆 Programme delays from poor sequencing

• 🔧 Subpar finishes that impact asset value

• 🔁 Costly late-stage variations to fix design problems that weren’t resolved properly up front

  
  

And this is the kicker:

You didn’t save £20k — you deferred £40k in risks.

And when they show up, you’ll be the one paying for them — either now, or later when you try to sell or refinance.

When it works - And When it Doesn't

Now to be clear — Design & Build can work.

It works when:

• The client knows exactly what they want

• The design is fully developed before tender

• The employer’s requirements are watertight

• A skilled architect is retained as client-side advisor

  
  

It does not work when:

• You’re still figuring out the brief

• You don’t have detailed performance specs

• You’re relying on the contractor to “sort it out”

  
  

So if you're going to hand over control — you’d better be very, very confident that the team receiving it understands exactly what matters to you.

Or better yet — don’t hand it over. Let your architect lead all the way through, and retain a contractor who respects the design, not rewrites it.